new toilet burbling

Hi, and thanks in advance for any possible help.

I come by way of John Bridge tile forums, I help out there a little, but kind of keep up with the pro discussions mostly.

Anyways, I am remodelling a main floor bath in a 1950's cape style house upstate New York. Yesterday was able to grout the tile floor and set our new toilet. The original copper / brass flange had some height issues, so I cut that out and fit in a new PVC flange with a length of 3" pipe and connected to the 3" copper line with a Fernco. No trouble.

When we flush the upstairs toilet, the downstairs burbles quite violently ( IMO ) almost thinking we had a bidet !

This was happening before the re-model, and acting on some local yocal advice, I installed a AAV above my new downstairs sink which connects to the 3" drain line from upstairs. There is a Y copper fitting in basement that catches the upstairs stack ( shower, toilet, sink ) and main floor sink, and a seperate 3" line for main floor toilet.

Not sure what other info to give, other than it is a public sewer, does not seem to have obstructions, the one toilet is brand new, the upstairs may be 4-5yrs old. I have noticed bees in the stack vent in the past, I have just come down from the roof, and there is no sign of them, but I hosed into the pipe for about 5-6mins, with no back up.

We all like pichers over there, so I have attached a few showing the AAV, and one of the underside of the upstairs toilet. The toilet has the vent connecting right to the ' heel ' of that elbow fitting, and the shower drain connects just below.

Thanks again for any help !


These are used with the vent at the top.

Looks like you just might want a real vent!

You had vent problems before, and the vent location that you've chosen didn't make it any better. The new toilet has less water in the bowl so gurgles with more noise.

Is there a solution ?

Yes, it involves redoing the pipes properly. You need proper venting to stop this problem. Was this remodel job done by a licensed plumber with permits and inspections?

In a way it was, The local yocal is a family friend who is liscensed and engineered the venting. I did what he said to save labor $$. I will call him this morning.

Though there does not appear to be any obstruction in the ' heel ' of that upstairs toilet elbow, I may pull the upstairs toilet and inspect this heel connection.

Venting a toilet through a heel 90 is a no no and the sink below needs to be revented without the AAV. How the toilet below is vented and tied in is a big factor. Really you've got a bunch of fixing to do and I wouldn't put in any more walls ceilings and floors until it gets fixed. A plumber on-site would probably be a great idea!

The fitting can only go this way

gurgle

An automatic vent does nothing for your problem. There is a good chance that your main sewer is partially plugged creating a pressure issue which causes the bubbling.

I'm also betting the toilet on the lower floor is 12" from a 90 at the bse of the copper line coming down without a vent.

Thanks again for your time, it is appreciated. I have called my plumber friend and he is going to find time to come by and ' look ' again. We'll see what he comes up with.

I'll attach a pic of the piping in the basement. I think the toilet IS less than 12" from and elbow, or real close to it, as seen here.

Plumber Toilet

Just re-pipe it. There is no telling what nasty problems wait for you down the road in this thing.. It looks like a rather simple re-pipe.

In the photo above there is a 3x2 wye? running into a no-hubbed pvc line going downhill, whats that?

I completely agree with HJ on this......I have ran into this problem a few times and after playing with the venting and drainage you still have the same problem! This is not to say that there isn't any room for concern with your setup because there is, but I would certainly get someone to take a peek down the main sewer and see whats up.